JP5444873B2 - FUEL CELL SYSTEM AND METHOD FOR OPERATING FUEL CELL SYSTEM - Google Patents

Description

  The present invention relates to a fuel cell system including a hydrogen generation device that generates a fuel gas containing hydrogen as a main component from a source gas and water using a catalyst, and a method for operating the fuel cell system.

  Some conventional fuel cell systems include a water flow meter that measures the flow rate of water supplied to the hydrogen generator (see, for example, Patent Document 1). FIG. 5 shows a conventional fuel cell system described in Patent Document 1. In FIG.

  In FIG. 5, the hydrogen generator 101 generates a fuel gas mainly composed of hydrogen from the raw material gas and the water supplied by the reforming water pump 104. The fuel gas generated in the hydrogen generator 101 is supplied to the fuel cell 102 and generates electricity by electrochemically reacting with air supplied by an air supply pump (not shown). The fuel gas that has not been used for power generation is discharged from the fuel cell 102 and supplied to the burner 103. Air is also supplied to the burner 103 by the combustion fan 106 and burned together with the fuel gas to keep the catalyst of the hydrogen generator 101 at a high temperature.

  Furthermore, the flow rate of water supplied to the hydrogen generator 101 was detected using a water flow meter 105.

JP 2007-109590 A

  In the hydrogen generator 101, a catalyst for generating fuel gas generally includes ruthenium-containing catalyst or nickel-containing catalyst. When only the hydrocarbon as the raw material gas is supplied to these catalysts at a high temperature, the carbon as the component of the raw material gas is deposited on the catalyst and the catalytic performance is lowered.

  Therefore, it is important to determine at an early stage after supplying water for hydrogen generation, that is, whether or not water supply has started normally. Since the conventional fuel cell system shown in FIG. 5 includes the water flow meter 105, it is possible to determine whether or not water supply has started normally.

However, as shown in FIG. 5, in the conventional fuel cell system, it is impossible to realize a low-cost fuel cell system because the expensive water flow meter 105 detects whether or not the water supply has started normally. It was.

  Therefore, in view of the above-described conventional problems, the present invention makes it possible to determine an abnormality in water supply for hydrogen generation without using an expensive sensor such as a water flow meter, thereby reducing the cost. An object is to provide a battery system.

In order to achieve the above object, a fuel cell system of the present invention is produced by a hydrogen generator that generates a fuel gas mainly composed of hydrogen from a raw material gas and water using a catalyst, and the hydrogen generator. A fuel cell that generates power using the fuel gas and air; and from when the source gas is supplied to the hydrogen generator until the fuel gas generated by the hydrogen generator is supplied to the fuel cell. A combustor that burns the gas discharged from the hydrogen generator and heats the catalyst by burning the fuel gas that has not been consumed by the fuel cell after the fuel gas starts to be supplied to the fuel cell; Reforming water supply means for supplying water to the generator, and the hydrogen generator until the fuel gas in a state that can be supplied to the fuel cell in the hydrogen generator can be generated. The fuel bypass means for supplying the combustor, the combustion state detection means for detecting a combustion condition in the combustor without supplying gas al discharged to the fuel cell, the raw material to the hydrogen generator The reforming is performed if a predetermined condition is satisfied after the raw material gas supplied from the hydrogen generator is supplied to the combustor through the fuel bypass means and combustion is started in the combustor. and a control unit which Ru operates the water supply means, the Oite between from the reforming water supply means is operated until a predetermined time elapses, the reforming if they are stable combustion state of the combustor is maintained a determining means for abnormalities due to water supply from the water supply means to the hydrogen generator is lowered is determined to have occurred, a fuel cell system comprising a.

  According to this configuration, only the source gas is supplied to the hydrogen generator, the source gas discharged from the hydrogen generator is supplied to the combustor through the fuel bypass means, and combustion is started in the combustor. When the quality water supply means is operated and the reforming water supply means starts supplying water to the hydrogen generator, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state is also transiently changed. Although it becomes unstable, the transiently unstable combustion state is detected by the combustion state detecting means, and the judging means is based on the detected value indicating the unstable combustion state. Can be determined.

  Further, only the raw material gas is supplied to the hydrogen generator, the raw material gas discharged from the hydrogen generator is supplied to the combustor through the fuel bypass means, and combustion is started in the combustor, and then the reforming water is supplied. In the case where water cannot be supplied from the reforming water supply means to the hydrogen generator due to some abnormality, the stable combustion state is maintained even after the reforming water supply means is operated. This stable combustion state is detected by the combustion state detection means, and the determination means can determine that “the water supply is abnormal” based on the detected value representing the stable combustion state.

  Therefore, it is possible to determine the abnormality of the water supply for hydrogen generation using a relatively inexpensive combustion state detection means instead of an expensive sensor such as a water flow rate sensor, thereby reducing the cost of the fuel cell system. Can be realized.

The operating method of the fuel cell system of the present invention is an operating method of a fuel cell system comprising the constituent elements of the fuel cell system of the present invention, wherein only the raw material gas is supplied to a hydrogen generating device to generate the hydrogen A raw material gas combustion step in which the raw material gas discharged from the apparatus is supplied to the combustor through the fuel bypass means and burned; a supply of the raw material gas in the raw material gas combustion step; and a gas discharged from the hydrogen generator A water supply start step of starting a water supply operation to the hydrogen generator by the reforming water supply means while continuing combustion in the combustor, and a predetermined amount from the start of the water supply operation by the reforming water supply means Oite until elapsed time, the water supply amount of long said is maintained stable combustion state of the combustor from the reforming water supply means to the hydrogen generator is lowered Abnormal due to that is the operation method of a fuel cell system having a determination step of determining to have occurred.

  According to this operation method, the process shifts from the raw material gas combustion process to the water supply start process, so that a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state is also transiently unstable. However, in the determination process of the next process, the combustion state that is transiently unstable is detected by the combustion state detection means, and the determination means determines that the water supply is based on the detected value that represents the unstable combustion state. Is not abnormal ”.

  In addition, if water supply to the hydrogen generator cannot be performed due to some abnormality when the water supply operation for reforming water supply is started in the water supply start process, a large amount of raw material gas is combusted after the water supply operation is started. However, the combustion state is also stable, but in the next determination step, this stable combustion state is detected by the combustion state detection means, and based on the detected value representing the stable combustion state. The determination means can determine that “the water supply is abnormal”.

  Therefore, it is possible to determine the abnormality of the water supply for hydrogen generation using a relatively inexpensive combustion state detection means instead of an expensive sensor such as a water flow rate sensor, thereby reducing the cost of the fuel cell system. Can be realized.

  According to the fuel cell system and the operation method of the fuel cell system of the present invention, instead of an expensive sensor such as a water flow rate sensor, a relatively inexpensive combustion state detection such as a carbon monoxide concentration detector or a flame detector is used. Since it is possible to determine an abnormality in the supply of water for hydrogen generation using the means, it is possible to reduce the cost of the fuel cell system.

1 is a block diagram of a fuel cell system according to Embodiment 1 of the present invention. Flowchart showing the water supply abnormality determination operation of the fuel cell system of the embodiment Block diagram of a fuel cell system according to Embodiment 2 of the present invention Flowchart showing the water supply abnormality determination operation of the fuel cell system of the embodiment Block diagram of a conventional fuel cell system

According to a first aspect of the present invention, a hydrogen generator that generates a fuel gas mainly composed of hydrogen from a raw material gas and water using a catalyst, and power generation using the fuel gas and air generated by the hydrogen generator. The fuel cell to be performed and the gas discharged from the hydrogen generator until the fuel gas generated by the hydrogen generator is supplied to the fuel cell after the source gas is supplied to the hydrogen generator. A combustor that heats the catalyst by burning the fuel gas that has not been consumed by the fuel cell after the fuel gas starts to be supplied to the fuel cell; and reformed water that supplies water to the hydrogen generator And supplying gas discharged from the hydrogen generator until the fuel gas in a state that can be supplied to the fuel cell can be generated in the hydrogen generator. The fuel bypass means for supplying the combustor, the exhaust from the combustion state detecting means for detecting a combustion condition in the combustor, the hydrogen generator by supplying only the source gas to the hydrogen generator without the raw material gas to be supplied to the combustor through the fuel bypass means, wherein said reforming water supply means Ru to operate the control unit satisfies a predetermined condition after starting the combustion in the combustor, the Oite between from by operating the reforming water supply means until a predetermined time elapses, the water supply from the reforming water supply means if the is maintained stable combustion state of the combustor into the hydrogen generator the amount is a fuel cell system and a determination means for determining that an abnormality has occurred due to degraded.

  According to the above configuration, only the source gas is supplied to the hydrogen generator, the source gas discharged from the hydrogen generator is supplied to the combustor through the fuel bypass means, and combustion is started in the combustor. When the quality water supply means is operated and the reforming water supply means starts supplying water to the hydrogen generator, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state is also transiently changed. Although it becomes unstable, the transiently unstable combustion state is detected by the combustion state detecting means, and the judging means is based on the detected value indicating the unstable combustion state. Can be determined.

  Further, only the raw material gas is supplied to the hydrogen generator, the raw material gas discharged from the hydrogen generator is supplied to the combustor through the fuel bypass means, and combustion is started in the combustor, and then the reforming water is supplied. In the case where water cannot be supplied from the reforming water supply means to the hydrogen generator due to some abnormality, the stable combustion state is maintained even after the reforming water supply means is operated. This stable combustion state is detected by the combustion state detection means, and the determination means can determine that “the water supply is abnormal” based on the detected value representing the stable combustion state.

  Therefore, it is possible to determine the abnormality of the water supply for hydrogen generation using a relatively inexpensive combustion state detection means instead of an expensive sensor such as a water flow rate sensor, thereby reducing the cost of the fuel cell system. Can be realized.

  In a second invention, a gas concentration detector for detecting a gas concentration of a predetermined gas in the combustion exhaust gas discharged from the combustor is used as the combustion state detection means in the first invention.

  When the supply of water to the hydrogen generator is started, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, so that the combustion state becomes transiently unstable and a specific amount in the combustion exhaust gas The gas concentration changes. Therefore, it is possible to determine an abnormality in water supply for hydrogen generation by detecting the concentration of a specific gas whose concentration changes when the combustion state in the combustion exhaust gas becomes unstable and determining whether or not a predetermined condition is satisfied. .

  Also, as combustion state detection means for detecting the stability and instability of the combustion state, carbon monoxide temporarily generated by combustion, oxygen that is excessively supplied to the combustor and discharged without being combusted, and not combusted by the combustor By using a gas concentration detector that detects the concentration of hydrocarbon gases such as methane and propane contained in the raw material gas discharged to the gas, the detection value of the gas concentration that changes according to the stability and instability of the combustion state, It is useful because the determination means can determine whether or not the water supply is abnormal.

  In a third invention, the predetermined gas in the second invention is carbon monoxide.

  When the supply of water to the hydrogen generator is started, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, so that the combustion state becomes transiently unstable and monoxide in the combustion exhaust gas Carbon concentration increases. Therefore, if the concentration of carbon monoxide in the combustion exhaust gas is equal to or higher than the predetermined concentration, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state becomes transiently unstable. It can be assumed that the concentration of carbon monoxide in the fuel has increased, so it can be determined that the water supply is normal, and conversely, if the concentration of carbon monoxide in the combustion exhaust gas is less than the predetermined concentration, the combustion remains stable. Therefore, it can be determined that the water supply is abnormal.

  In a fourth invention, the predetermined gas in the second invention is a methane or propane hydrocarbon-based gas contained in a raw material gas.

  When the supply of water to the hydrogen generator is started, a large amount of source gas is transiently supplied to the combustor by the evaporated water, so that the combustion state becomes transiently unstable, and a part of the source gas is Since it is discharged unburned, the methane or propane hydrocarbon gas in the combustion exhaust gas increases. Therefore, if the concentration of the methane or propane hydrocarbon gas in the combustion exhaust gas is equal to or higher than the predetermined concentration, a large amount of source gas is transiently supplied to the combustor by the evaporated water, and the combustion state is transiently inactivated. It can be estimated that the concentration of methane or propane hydrocarbon gas in the combustion exhaust gas has increased, so it can be determined that the water supply is normal, and conversely, the concentration of methane or propane hydrocarbon gas in the combustion exhaust gas Is less than the predetermined concentration, it can be determined that the water supply is abnormal because the combustion is maintained in a stable state.

According to a fifth aspect of the present invention, the maximum value of the gas concentration is less than a predetermined concentration value after the determination unit in the third or fourth aspect of the invention operates the reforming water supply unit until a predetermined time elapses. In this case, it is determined that an abnormality has occurred due to a decrease in the amount of water supplied from the reforming water supply means to the hydrogen generator.

  If a gas concentration detector that detects the concentration of carbon monoxide or methane or propane hydrocarbon gas in the flue gas discharged from the combustor is used as the combustion state detection means, If the maximum value of the gas concentration from when the quality water supply means is operated until a predetermined time elapses is smaller than the predetermined concentration value, it is determined that the water supply from the reforming water supply means to the hydrogen generator is abnormal. If the maximum gas concentration from when the reforming water supply means is operated until a predetermined time elapses is equal to or greater than the predetermined concentration value, water supply from the reforming water supply means to the hydrogen generator is normal. It can be judged that.

  In a sixth aspect of the invention, the predetermined gas in the second aspect of the invention is oxygen.

When the supply of water to the hydrogen generator is started, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, so that the oxygen necessary for the combustion of the raw material gas is insufficient and transient oxygen The concentration decreases. Therefore, if the oxygen concentration in the combustion exhaust gas decreases to a predetermined concentration or less, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state becomes transiently unstable. Since it can be assumed that the oxygen concentration has decreased, it can be determined that the water supply is normal, and conversely, if the oxygen concentration in the combustion exhaust gas exceeds the predetermined concentration, the combustion is maintained in a stable state, so the water supply amount It can be determined that an abnormality has occurred due to a drop in the .

According to a seventh aspect of the present invention, when the determination unit according to the sixth aspect of the present invention has a minimum value of the gas concentration greater than a predetermined concentration value after a predetermined time elapses after the reforming water supply unit is operated, It is determined that an abnormality has occurred due to a decrease in the amount of water supplied from the reforming water supply means to the hydrogen generator.

  When a gas concentration detector that detects the concentration of oxygen in the combustion exhaust gas discharged from the combustor is used as the combustion state detection means, a predetermined time elapses after the reforming water supply means is operated as the determination means. If the minimum value of the gas concentration is higher than the predetermined concentration value, it is determined that the water supply from the reforming water supply unit to the hydrogen generator is abnormal and the reforming water supply unit is operated before the predetermined value. When the minimum value of the gas concentration until the elapse of time is equal to or less than the predetermined concentration value, it can be determined that the water supply from the reforming water supply means to the hydrogen generator is normal.

An eighth invention uses a flame detector that detects a flame in the combustor and outputs a current as the combustion state detection means in the first invention, and the determination means uses the reformed water supply means. When the minimum value of the output current of the flame detector after the operation until a predetermined time elapses is greater than a predetermined value, the amount of water supplied from the reforming water supply means to the hydrogen generator decreases. It is determined that an abnormality has occurred .

  When the supply of water to the hydrogen generator is started, a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, so that the flame floats from the combustor and the output of the flame detector Current decreases. Conversely, since there is no supply of water to the hydrogen generator, a flame is stably formed in the combustor and the output current of the flame detector is also stable when there is no transient large amount of source gas supply. Therefore, if the minimum value of the output current of the flame detector after the reforming water supply means is operated until a predetermined time has elapsed is greater than the predetermined value, water supply from the reforming water supply means to the hydrogen generator If the minimum value of the output current of the flame detector after the predetermined time elapses after operating the reforming water supply means is less than the predetermined value, It can be determined that the water supply from the reforming water supply means to the hydrogen generator is normal.

  In addition, if a flame detector that detects the flame in the combustor is used as a combustion state detection means for detecting the stability and instability of the combustion state, when there is a large amount of raw material gas supply accompanying the start of water supply, the flame The flame detector floats from the combustor and the output current of the flame detector decreases. When there is no supply of a large amount of raw material gas, the flame is stably formed in the combustor and the output current of the flame detector is also stable. This is useful because it is possible to determine whether or not the water supply is abnormal by the determination means based on the output signal of the flame detector, which is a detection value that changes according to the stability and instability of the combustion state.

According to a ninth aspect, in the first to eighth aspects, when the determination unit determines that an abnormality has occurred due to a decrease in the amount of water supplied from the reforming water supply unit to the hydrogen generator, The hydrogen generator is stopped, and when the water supply from the reforming water supply means to the hydrogen generator is abnormal, the abnormality is detected and related to the operation of the hydrogen generator (and the hydrogen generator). Peripheral equipment) will be stopped, so the user of the fuel cell system will notice that the fuel cell system has stopped abnormally and contact the service company to perform inspections, failure diagnosis, parts replacement, failure repair, etc. Although the fuel cell cannot generate power, the raw materials are burned wastefully, the power used to operate the hydrogen generator and its peripheral devices is wasted, and the materials such as the catalyst are abnormally deteriorated. It can be prevented.

A tenth aspect of the invention includes, in addition to the first to ninth aspects, a display for displaying the operating state of the fuel cell system, wherein the judging means supplies water from the reforming water supply means to the hydrogen generator. When it is determined that an abnormality has occurred due to a decrease in the supply amount , the display indicates that the water supply from the reforming water supply means to the hydrogen generator is abnormal. The fuel cell system user or service person can know from the display that the water supply from the reforming water supply means to the hydrogen generator is abnormal. Responses such as replacement and fault repair can be performed quickly and without waste.

In an eleventh aspect of the invention, a hydrogen generator that generates a fuel gas mainly composed of hydrogen from a raw material gas and water using a catalyst, and power generation using the fuel gas and air generated by the hydrogen generator. The fuel cell to be performed and the gas discharged from the hydrogen generator until the fuel gas generated by the hydrogen generator is supplied to the fuel cell after the source gas is supplied to the hydrogen generator. reforming water supply and a combustor for heating said catalyst by burning the fuel gas not consumed, the water to the hydrogen generator in the fuel cell from the fuel gas starts to be supplied to the fuel cell is Supply means and gas discharged from the hydrogen generator until the fuel gas in a state that can be supplied to the fuel cell in the hydrogen generator can be generated. A fuel cell system operating method comprising: fuel bypass means for supplying to the combustor without combustion; and combustion state detection means for detecting the combustion state in the combustor, wherein the hydrogen generator A raw material gas combustion step of supplying only the raw material gas and discharging the raw material gas discharged from the hydrogen generator to the combustor through the fuel bypass means, and supplying the raw material gas in the raw material gas combustion step And a water supply start step for starting a water supply operation to the hydrogen generator by the reforming water supply means while continuing combustion in the combustor of the gas discharged from the hydrogen generator, and the reformed water supply Oite between the start of the water supply operation by means until a predetermined time elapses, the from the reforming water supply means if a stable combustion state of the combustor is maintained Water supply to hydrogen generating device is an operating method of a fuel cell system having a determination step of determining that the abnormality due to have decreased occurs.

  According to this operation method, the process shifts from the raw material gas combustion process to the water supply start process, so that a large amount of raw material gas is transiently supplied to the combustor by the evaporated water, and the combustion state is also transiently unstable. However, in the judgment process of the next process, the combustion state that has become transiently unstable is detected by the combustion state detection means, and based on the detected value that represents the unstable combustion state, It can be judged that there is no.

  In addition, if water supply to the hydrogen generator cannot be performed due to some abnormality when the water supply operation for reforming water supply is started in the water supply start process, a large amount of raw material gas is combusted after the water supply operation is started. However, the combustion state is also stable, but in the next determination step, this stable combustion state is detected by the combustion state detection means, and based on the detected value representing the stable combustion state. The determination means can determine that “the water supply is abnormal”.

  Therefore, it is possible to determine the abnormality of the water supply for hydrogen generation using a relatively inexpensive combustion state detection means instead of an expensive sensor such as a water flow rate sensor, thereby reducing the cost of the fuel cell system. Can be realized.

A twelfth aspect of the invention is the operation method of the fuel cell system, further comprising an indicator for displaying an operation state of the fuel cell system in addition to the eleventh aspect, wherein the reforming water supply means is provided in the determination step. When a determination is made that an abnormality has occurred due to a decrease in the amount of water supplied to the hydrogen generator, a display step for displaying the abnormality is further provided. The fuel cell system user or service person can know that the water supply to the generator is abnormal by the display on the display, and the service person can perform inspections, trouble diagnosis, parts replacement, trouble repair, etc. Can be done quickly without waste.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments. The same reference numerals are given to the same components as those of the above-described embodiment, and the detailed description thereof is omitted.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the fuel cell system according to Embodiment 1 of the present invention.

As shown in FIG. 1, the fuel cell system in the present embodiment generates a fuel gas mainly composed of hydrogen by steam reforming a hydrocarbon-based raw material gas such as city gas or propane gas using a catalyst. A hydrogen generator 1 that performs the power generation by supplying the fuel gas and air generated by the hydrogen generator 1, a burner 3 that heats the catalyst included in the hydrogen generator 1, and the hydrogen generator 1 A raw material gas supply channel 4 through which the raw material gas supplied to the hydrogen generator 1 flows, a reformed water supply channel 5 through which water supplied to the hydrogen generator 1 flows, and a reformed water that supplies water to the hydrogen generator 1 A pump 6, a fuel gas supply flow path 7 for supplying the fuel gas generated by the hydrogen generator 1 to the fuel cell 2, and a fuel gas discharge flow path for discharging the fuel gas not used for power generation in the fuel cell 2 8 and from the middle of the fuel gas supply channel 7 A bypass flow path 9 that merges with the fuel gas discharge flow path 8, electromagnetic valves 10, 11, 12 that supply and shut off the fuel gas flowing through the flow paths 7, 8, 9, and the burner 3 A combustion fan 13 for supplying combustion air to the combustion chamber, a carbon monoxide concentration detector 14 for detecting the concentration of carbon monoxide in the combustion exhaust gas discharged from the burner 3, and a combustion exhaust gas flow for discharging the combustion exhaust gas outside the system A control unit 16 that controls a series of operations of the channel 15, the hydrogen generator 1, a determination unit 17 that determines whether the water supply is abnormal based on the concentration of the carbon monoxide concentration detector 14, and a fuel cell system The display 18 which displays the driving | operation state of is provided.

  The burner 3 and the reforming water pump 6 as constituent members in the present embodiment are examples of specific implementations of the combustor and the reforming water supply unit, respectively. The carbon monoxide concentration detector 14 is an example of a concrete implementation of a gas concentration detector as a combustion state detection means.

  Further, the fuel gas supply flow path 7, the fuel gas discharge flow path 8, the bypass flow path 9, and the electromagnetic valves 10, 11, and 12 as constituent members in the present embodiment are specific implementations of the fuel bypass means. It is an example.

  The fuel cell system in the present embodiment is supplied from a reforming water supply channel 5 and a hydrocarbon-based source gas such as city gas or propane gas supplied from the source gas supply channel 4 using a catalyst. A hydrogen generating device 1 for generating a fuel gas mainly composed of hydrogen from the water, a fuel gas generated by the hydrogen generating device 1 and supplied from the fuel gas supply flow path 7, and an air supply means (not shown) The fuel cell 2 that generates power using oxygen contained in the air supplied from the above) and the combustion air is supplied by the combustion fan 13 and the hydrogen generator 1 starts supplying the source gas to the hydrogen generator 1. Until the generated fuel gas is supplied to the fuel cell 2, the gas discharged from the hydrogen generator 1 is burned using the combustion air supplied by the combustion fan 13, and the fuel gas is supplied to the fuel cell 2. Beginning A burner (combustor) 3 that heats the catalyst in the hydrogen generator 1 by combusting fuel gas that has not been consumed in the fuel cell 2 by using combustion air supplied by the combustion fan 13, and reforming A reformed water pump (reformed water supply means) 6 that is provided in the water supply channel 5 and supplies water to the hydrogen generator 1 and a fuel gas that can be supplied to the fuel cell 2 in the hydrogen generator 1 can be generated. In order to supply the gas discharged from the hydrogen generator 1 to the burner (combustor) 3 without supplying it to the fuel cell 2 until it becomes (fuel gas supply flow path 7 and fuel cell 2 A fuel gas discharge passage 8 that discharges fuel gas that has not been used for power generation and supplies the burner (combustor) 3 to the fuel gas discharge passage 8 branches from the middle of the fuel gas supply passage 7. Bypass passage 9 and fuel gas supply The fuel cell from the junction of the solenoid valve 10 provided in the fuel gas supply channel 7 on the fuel cell 2 side from the branch point to the bypass channel 9 in the path 7 and the bypass channel 9 in the fuel gas discharge channel 8 Combustion exhaust gas flow for discharging the combustion exhaust gas of the burner (combustor) 3 from the electromagnetic valve 11 provided in the fuel gas discharge flow path 8 on the second side, the electromagnetic valve 12 provided in the bypass flow path 8) A carbon monoxide concentration detector (combustion) that detects the state of combustion in the burner (combustor) 3 by detecting the concentration of carbon monoxide in the combustion exhaust gas provided in the passage 15 and discharged from the burner (combustor) 3. (State detection means) 14, a control unit 16, and a display 18 that displays the operation state of the fuel cell system.

The control unit 16 supplies only the source gas to the hydrogen generator 1 and supplies the source gas discharged from the hydrogen generator 1 to the burner (combustor) 3 through the fuel bypass means. If a predetermined condition such that the temperature of the catalyst reaches a predetermined temperature after starting combustion is satisfied, the reforming water pump (reforming water supply means) 6 is operated, and the reforming water pump (reforming water supply means) 6 is operated. The detected value (the carbon monoxide in the combustion exhaust gas discharged from the burner (combustor) 3) detected by the carbon monoxide concentration detector (combustion state detection means) 14 after the operation of Whether or not the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal is determined based on whether or not the detected value of the concentration satisfies a predetermined condition (200 ppm or more). (Concentration of carbon monoxide in combustion exhaust gas Detection value has a determination means 17 which normally if there is be more than 200ppm, if the remains of less than 200ppm abnormality determination) to. When the control unit 16 determines that the water supply from the reforming water pump (reforming water supply unit) 6 to the hydrogen generator 1 is abnormal by the determination unit 17, the control unit 16 supplies the water to the display unit 18. Is displayed, and the operation of the peripheral devices such as the hydrogen generator 1 and the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation of the hydrogen generator 1 is stopped. At the same time, for example, the source gas supply flow path 4 is closed by a solenoid valve (not shown), and the supply of the source gas to the hydrogen generator 1 is stopped.

  The operation of the fuel cell system of the present embodiment configured as described above will be described below.

  The hydrogen generator 1 is supplied with a city gas from which an odorous component has been previously removed by a desulfurization catalyst or the like as a source gas through the source gas supply channel 4. In addition, water is supplied to the hydrogen generator 1 through the reformed water supply channel 5 by the reformed water pump (reformed water supply means) 6. And in the hydrogen production | generation apparatus 1, the fuel gas which has hydrogen as a main component is produced | generated by making the supplied raw material gas and water react on a catalyst.

  On the other hand, the fuel cell 2 electrochemically combines the fuel gas generated by the hydrogen generator 1 and supplied from the fuel gas supply flow path 7 with the oxygen contained in the air supplied from the air supply means (not shown). Electricity is generated by reacting with. The fuel gas not used for power generation in the fuel cell 2 (not consumed in power generation) is discharged from the fuel gas discharge flow path 8 and supplied to the burner (combustor) 3.

  Then, the burner (combustor) 3 burns the fuel gas supplied from the fuel gas discharge passage 8 using the combustion air supplied by the combustion fan 13 to heat the catalyst in the hydrogen generator 1 at a high temperature. Hold on. The combustion exhaust gas from the burner (combustor) 3 is discharged out of the system through the combustion exhaust gas passage 15.

  However, since the temperature of the catalyst is not sufficiently raised when the hydrogen generator 1 is started up, the function as a catalyst cannot be sufficiently achieved, and the fuel gas discharged from the hydrogen generator 1 has a high value. The concentration of carbon monoxide is included.

  Since the high concentration of carbon monoxide reduces the catalytic performance of the fuel cell 2, the supply of water to the hydrogen generator 1 by the reforming water pump (reformed water supply means) 6 is supplied to the hydrogen generator 1. Delaying from the supply of the raw material gas, for a while, the electromagnetic valves 10 and 11 are closed, the electromagnetic valve 12 is opened, the bypass passage 9 is opened, and the gas discharged from the hydrogen generator 1 is The fuel is supplied to the burner (combustor) 3 without being supplied to the fuel cell 2.

  The burner (combustor) 3 burns the gas supplied from the fuel gas discharge passage 8 using the combustion air supplied by the combustion fan 13 to heat the catalyst in the hydrogen generator 1 to generate hydrogen. When the temperature of the catalyst in the apparatus 1 rises to a predetermined temperature, the reforming water pump (reforming water supply means) 6 starts supplying water to the hydrogen generator 1. When water supply to the hydrogen generator 1 is started, a large amount of raw material gas is transiently supplied to the combustor by the water (water vapor) evaporated by heat, and the combustion state becomes transiently unstable.

Eventually, when the carbon monoxide in the fuel gas generated by the hydrogen generator 1 is sufficiently reduced to a concentration that does not reduce the catalytic performance of the fuel cell 2, the shutoff valves 10 and 11 are opened and the shutoff valve 12 is closed. Thus, the bypass channel 9 is closed and the fuel gas is supplied to the fuel cell 2 through the fuel gas supply channel 7.

  Further, the carbon monoxide concentration detector 14 disposed in the combustion exhaust gas flow path 15 monitors the carbon monoxide concentration in the combustion exhaust gas, and the judgment means 17 of the control unit 16 includes a reforming water pump (reforming water). The detected value of the concentration of carbon monoxide in the combustion exhaust gas detected by the carbon monoxide concentration detector 14 from the time when the water supply means 6 is operated until a predetermined time elapses is maintained below 200 ppm. If it is determined that there is an abnormality, the display 18 displays that the water supply is abnormal, and the hydrogen generator 1 and the reforming water pump (reforming water supply means) related to the operation of the hydrogen generator 1 are displayed. ) Stop the operation of peripheral devices such as 6 and the combustion fan 13 and stop the supply of the source gas to the hydrogen generator 1 by closing the source gas supply flow path 4 with a solenoid valve (not shown), for example. To do.

  The carbon monoxide concentration in the combustion exhaust gas detected by the carbon monoxide concentration detector 14 after a predetermined time (30 seconds) has elapsed since the reforming water pump (reforming water supply means) 6 is operated. If the detected value exceeds a predetermined value, the control unit 16 determines that the combustion state is unstable, determines that the system operation is abnormal, and the indicator 18 indicates that the combustion state is unstable. The display showing that is performed. The display indicating that the combustion state is unstable may be a character string such as “burning abnormality”, or may be a so-called error code in which alphabets and numbers are combined.

  Next, the water supply abnormality determination operation of the fuel cell system of the present embodiment will be described using the flowchart shown in FIG.

  When an operation for supplying fuel gas from the hydrogen generator 1 to the fuel cell 2 (operation for generating electricity with the fuel cell 2) is started, first, a raw material gas combustion process (supplying only the raw material gas to the hydrogen generator 1) Then, the step of supplying the raw material gas discharged from the hydrogen generator 1 to the burner (combustor) 3 through the fuel bypass means and burning it is started.

  In the source gas combustion process, first, only source gas is supplied to the hydrogen generator 1 through the source gas supply channel 4 (S101). At this time, since the solenoid valves 10 and 11 are in the closed state and the solenoid valve 12 is in the open state, the raw material gas supplied to the hydrogen generator 1 is supplied from the hydrogen generator 1 to the fuel gas supply flow path 7 and the bypass. The gas is supplied to the burner (combustor) 3 through the flow path 9 and the fuel gas discharge flow path 8.

  Combustion air is also supplied to the burner (combustor) 3 by the combustion fan 13, and ignition and combustion are started by operating an igniter (not shown) (S102). Whether the catalyst of the hydrogen generator 1 is heated by the combustion of the burner (combustor) 3 and whether or not the temperature has risen to a temperature at which water can be supplied to the hydrogen generator 1, is necessary in the periphery of the catalyst of the hydrogen generator 1. Is determined based on the temperature detected by a temperature detector (not shown) provided in (S103), and waits for the temperature to rise to a temperature at which water can be supplied to the hydrogen generator 1.

  And when it will be in the temperature state which can supply water to the hydrogen production | generation apparatus 1, a raw material gas combustion process will be complete | finished and it will be discharged | emitted from a water supply start process (supply of the raw material gas in a raw material gas combustion process and a hydrogen production | generation apparatus) The process proceeds to the step of starting the water supply operation to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 while continuing the combustion of the gas in the burner (combustor) 3.

  In the water supply start process, water supply operation to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 is started (S104). When the water supply start process is completed, a determination process (a carbon monoxide concentration detector (combustion state detection means) from the start of the water supply operation by the reforming water pump (reformed water supply means) 6 until a predetermined time elapses). The process proceeds to a step of determining whether or not the water supply is abnormal depending on whether the detected value of the carbon monoxide concentration detected by 14 satisfies a predetermined condition or not.

  In the determination step, it is determined whether or not the carbon monoxide concentration in the combustion exhaust gas discharged from the burner (combustor) 3 detected by the carbon monoxide concentration detector 14 is equal to or higher than a predetermined concentration value of 200 ppm. The means 17 determines (S105).

  The carbon monoxide concentration detector after the control unit 16 causes the reforming water pump (reforming water supply means) 6 to perform the water supplying operation until a predetermined time (in this embodiment, 30 seconds) elapses. When the carbon monoxide concentration in the flue gas discharged from the burner (combustor) 3 detected by the fuel gas 14 becomes 200 ppm or more which is a predetermined concentration value, hydrogen generation by the reforming water pump (reforming water supply means) 6 The determination means 17 determines that the water supply to the apparatus 1 is normal, branches S105 to Yes, and proceeds to the next step S108, where carbon monoxide in the fuel gas generated by the hydrogen generator 1 is When the catalyst cell performance of the fuel cell 2 is sufficiently reduced to a level that does not deteriorate, the shut-off valves 10 and 11 are opened and the shut-off valve 12 is closed, thereby closing the bypass passage 9 and supplying the fuel gas to the fuel gas supply passage. 7 to the fuel cell 2 The fuel cell 2 electrochemically combines the fuel gas generated by the hydrogen generator 1 and supplied from the fuel gas supply flow path 7 and the oxygen contained in the air supplied from the air supply means (not shown). Electricity is generated by reacting with.

  If the control unit 16 causes the reforming water pump (reforming water supply means) 6 to perform the water supply operation, the carbon monoxide concentration will elapse between a predetermined time (in this embodiment, 30 seconds). If the concentration of carbon monoxide in the flue gas discharged from the burner (combustor) 3 detected by the detector 14 does not reach the predetermined concentration value of 200 ppm or more, the reforming water pump (reforming water supply means) 6 The determination means 17 determines that there is an abnormality in the water supply to the hydrogen generator 1 by S, branches S106 to the Yes side and proceeds to the next step S107, and the display 18 indicates that the water supply is abnormal. Display is performed (S107), and the operation of the peripheral devices such as the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation of the hydrogen generator 1 and the hydrogen generator 1 is stopped. The source gas supply flow path 4 is electromagnetic Closed (not shown) to stop the supply of the raw material gas to the hydrogen generator 1 (S109). These series of operations are controlled and operated by the control unit 16.

  In the present embodiment, the predetermined time from the start of water supply when determining whether or not there is an abnormality in the water supply to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 is used. , 30 seconds, but it is not necessarily strictly 30 seconds. The temperature rise time from the catalyst temperature at the start of the reforming water supply to the temperature at which no catalyst deterioration of the hydrogen generator 1 occurs in the absence of water supply. It can be set appropriately within a shorter time range.

  In the present embodiment, the predetermined concentration value of the carbon monoxide concentration is set to 200 ppm. However, it is not necessarily strictly 200 ppm, and is within a concentration value range equal to or lower than the carbon monoxide emission concentration allowed for the fuel cell system. Can be set appropriately. Further, it may be set in advance as described above, or may be set by the control unit 16 with reference to the concentration of carbon monoxide discharged in step S103 of the startup operation described above.

  When the reforming water supply is started in step S104, a large amount of source gas is transiently supplied to the burner 3 through the fuel gas supply channel 7, the bypass channel 9, and the fuel gas discharge channel 8 by the evaporated water. The combustion state becomes transiently unstable, and the concentration of carbon monoxide in the combustion exhaust gas increases.

  When the configuration and operation method of the fuel cell system in the present embodiment are taken, when the carbon monoxide concentration, which is a detected value representing the unstable combustion state, is generated above a predetermined concentration value (for example, 200 ppm), The determination means 17 can determine that “the water supply is not abnormal”.

  On the other hand, when the supply of reforming water is started in step S104, if water supply cannot be performed due to some abnormality, a large amount of source gas is supplied after the start of water supply to the fuel gas supply channel 7, the bypass channel 9, and the fuel gas. Since it is not supplied to the burner 3 through the discharge channel 8, the combustion state is stable and the carbon monoxide concentration in the combustion exhaust gas does not increase.

  When the carbon monoxide concentration in the stable combustion state is less than a predetermined concentration value (for example, 200 ppm), the determination means 17 can determine that “the water supply is abnormal”. Therefore, unlike the conventional fuel cell system, it is possible to determine an abnormality in the water supply for hydrogen generation without using an expensive sensor such as a water flow rate sensor, thereby realizing a reduction in cost of the fuel cell system. be able to.

  Further, taking the configuration and operating method of the fuel cell system in the present embodiment, the determination means 17 determines that the water supply is abnormal and displays on the display 18 that the water supply is abnormal. be able to. Therefore, when “water supply is abnormal”, it is possible to notify the user or maintenance person that “water supply is abnormal”.

  In the fuel cell system according to the present embodiment, the carbon monoxide concentration detector 14 is used as the gas concentration detector as the combustion state detection means, but the concentration of oxygen, which is another gas component in the combustion exhaust gas, is detected. The oxygen concentration detector to be used may be installed at a location equivalent to the carbon monoxide concentration detector 14 of FIG.

  In the case of the oxygen concentration detector, when the reforming water supply is started in step S104, a large amount of source gas is transiently transferred by the evaporated water through the fuel gas supply channel 7, the bypass channel 9, and the fuel gas discharge channel 8. Since it is supplied to the burner 3, the oxygen necessary for the combustion of the raw material gas is insufficient, and the oxygen concentration decreases transiently. Therefore, by changing step S105 of FIG. 2 to “oxygen concentration ≦ predetermined concentration value (for example, 2%)”, the oxygen concentration, which is a detection value representing an unstable combustion state, is changed to a predetermined concentration value (for example, 2%), the determination means 17 can determine that “the water supply is not abnormal”.

  On the other hand, if the water supply cannot be performed due to some abnormality when the reforming water supply is started in step S104, a large amount of raw material gas is supplied from the fuel gas supply flow path 7, the bypass flow path 9, the fuel gas discharge flow after the start of the water supply. Since it is not supplied to the burner 3 through the path 8, the combustion state is also stable and oxygen in the combustion exhaust gas does not decrease. When the oxygen concentration in the stable combustion state is a predetermined concentration value (for example, 2%) or more, the determination means 17 can determine that “the water supply is abnormal”. That is, even if an oxygen concentration detector that detects instead of the carbon monoxide concentration detector is used as the gas concentration detector as the combustion state detector, the same effect can be obtained.

  Also, “2%”, which is a predetermined concentration value of the oxygen concentration, is not limited to this, as in the case of the carbon monoxide concentration detector 14, and combustion below the carbon monoxide emission concentration allowed for the fuel cell system is realized. It can be appropriately set within the range of concentration values when operating with an excess air ratio within a possible range. Alternatively, it may be set in advance as described above, or may be set by the control unit 16 with reference to the oxygen concentration discharged in step S103 of the startup operation described above.

  In the fuel cell system according to the present embodiment, the carbon monoxide concentration detector 14 is used as the gas concentration detector as the combustion state detection means. However, the hydrocarbon-based gas contained in the raw material gas, for example, city gas, is used. A combustible gas concentration detector that detects the concentration of methane when using methane as the raw material gas and propane or butane when using LP gas as the raw material gas is provided at the same location as the carbon monoxide concentration detector 14 in FIG. May be installed.

  In the case of the combustible gas concentration detector, when the reforming water supply is started in step S104, a large amount of raw material gas is transiently converted into the fuel gas supply flow path 7, the bypass flow path 9, and the fuel gas discharge flow path 8 by the evaporated water. Since the gas is supplied to the burner 3, the combustion becomes transiently unstable and a part of the raw material gas is discharged unburned.

  Therefore, by changing step S105 in FIG. 2 to “combustible gas concentration ≧ predetermined concentration value (for example, 3000 ppm)”, the combustible gas concentration, which is a detection value indicating an unstable combustion state, is changed to a predetermined concentration value (for example, In the case where it has increased to 3000 ppm) or more, the determination means 17 can determine that “the water supply is not abnormal”.

  On the other hand, when the supply of reforming water is started in step S104, if water supply cannot be performed due to some abnormality, a large amount of source gas is supplied after the start of water supply to the fuel gas supply channel 7, the bypass channel 9, and the fuel gas. Since it is not supplied to the burner 3 through the discharge flow path 8, the combustion state is also stable, and the state in which the unburned raw material gas in the combustion exhaust gas is very small is maintained.

  When the combustible gas concentration in the stable combustion state is less than a predetermined concentration value (for example, 3000 ppm), the determination means 17 can determine that “the water supply is abnormal”. That is, even if a combustible gas concentration detector that detects instead of the carbon monoxide concentration detector 14 is used as the gas concentration detector as the combustion state detection means, the same effect can be obtained.

  Further, “3000 ppm”, which is a predetermined concentration value of the combustible gas concentration, is not limited to the same as in the case of the carbon monoxide concentration detector 14, and is appropriate within the range of the combustible gas discharge concentration allowable for the fuel cell system. Can be set to Alternatively, it may be set in advance as described above, or may be set by the control unit 16 based on the combustible gas concentration discharged in step S103 of the above-described start operation.

  The source gas is “city gas from which odorous components have been removed”, but is not limited thereto, and other hydrocarbon gas such as propane may be used.

  As described above, the fuel cell system according to the present embodiment includes the hydrogen generator 1 that generates a fuel gas containing hydrogen as a main component from the raw material gas and water using the catalyst, and the fuel generated by the hydrogen generator 1. The fuel cell 2 that generates power using gas and air, and the hydrogen generator 1 from when the raw material gas starts to be supplied to the hydrogen generator 1 until the fuel gas generated by the hydrogen generator 1 is supplied to the fuel cell 2 A burner (combustor) 3 that burns fuel gas that has not been consumed in the fuel cell 2 and heats the catalyst in the hydrogen generator 1 by burning the gas discharged from the fuel cell 2 and starting to be supplied to the fuel cell 2. Hydrogen generation until the hydrogen generator 1 can generate fuel gas that can be supplied to the fuel cell 2 by the reforming water pump (reforming water supply means) 6 that supplies water to the hydrogen generator 1 Waste from device 1 Bypass means (fuel gas supply flow path 7, fuel gas discharge flow path 8, bypass flow path 9 and electromagnetic) for supplying the burned gas to the burner (combustor) 3 without supplying it to the fuel cell 2 Valve 10, 11, 12), a carbon monoxide concentration detector (combustion state detection means) 14 for detecting the combustion state in the burner (combustor) 3, and a control unit 16. After supplying only the raw material gas to the generator 1 and supplying the raw gas discharged from the hydrogen generator 1 to the burner (combustor) 3 through the fuel bypass means, the combustion is started by the burner (combustor) 3 If the predetermined condition is satisfied, the reforming water pump (reforming water supply means) 6 is operated, and the carbon monoxide after the predetermined time elapses after the reforming water pump (reforming water supply means) 6 is operated. Concentration detector (combustion state detection means) 14 detects The determination unit 17 determines whether the water supply from the reforming water pump (reforming water supply unit) 6 to the hydrogen generator 1 is abnormal depending on whether the detection value to be satisfied satisfies the predetermined condition or not. It is a fuel cell system.

  According to the above configuration, only the raw material gas is supplied to the hydrogen generator 1, the raw material gas discharged from the hydrogen generator 1 is supplied to the burner (combustor) 3 through the fuel bypass means (bypass passage 9), After the combustion is started by the burner (combustor) 3, the reforming water pump (reforming water supply means) 6 is operated so that the reforming water pump (reforming water supply means) 6 is supplied to the hydrogen generator 1. When the supply of water is started, a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, and the combustion state becomes transiently unstable, but becomes transiently unstable. The combustion state is detected by the carbon monoxide concentration detector (combustion state detection means) 14 and the determination means 17 determines that “the water supply is not abnormal” based on the detected value indicating the unstable combustion state. Can do.

  Further, only the raw material gas is supplied to the hydrogen generator 1, and the raw material gas discharged from the hydrogen generator 1 is supplied to the burner (combustor) 3 through the fuel bypass means (bypass passage 9), and the burner (combustion) is supplied. The reforming water pump (reforming water supply means) 6 was operated after the combustion was started in the reactor 3, but the hydrogen generator 1 from the reforming water pump (reforming water supply means) 6 due to some abnormality. When the water cannot be supplied to the tank, the stable combustion state is maintained even after the reforming water pump (reforming water supply means) 6 is operated. Therefore, the stable combustion state is detected by the carbon monoxide concentration detector. Based on the detection value detected by the (combustion state detection means) 14 and representing a stable combustion state, the determination means 17 can determine that “the water supply is abnormal”.

  Therefore, an abnormality in water supply for hydrogen generation can be determined using a relatively inexpensive carbon monoxide concentration detector (combustion state detection means) 14 instead of an expensive sensor such as a water flow rate sensor. Thus, the cost reduction of the fuel cell system can be realized.

  As described above, the operation method of the fuel cell system according to the present embodiment includes the hydrogen generator 1 that generates a fuel gas mainly composed of hydrogen from the raw material gas and water using the catalyst, and the hydrogen generator 1 generates the fuel gas. The fuel cell 2 that generates power using the generated fuel gas and air, and the hydrogen gas from the start of supply of the raw material gas to the hydrogen generator 1 until the fuel gas generated by the hydrogen generator 1 is supplied to the fuel cell 2 A burner (combustion) that heats the catalyst in the hydrogen generator 1 by burning the fuel gas that has not been consumed in the fuel cell 2 after the gas discharged from the generator 1 is combusted and the fuel gas begins to be supplied to the fuel cell 2 3), a reforming water pump (reforming water supply means) 6 for supplying water to the hydrogen generator 1, and a fuel gas that can be supplied to the fuel cell 2 in the hydrogen generator 1. Until hydrogen generation equipment Fuel bypass means (fuel gas supply flow path 7, fuel gas discharge flow path 8, and bypass flow path 9 for supplying gas discharged from 1 to the burner (combustor) 3 without supplying it to the fuel cell 2 And a solenoid valve (10, 11, 12) and a carbon monoxide concentration detector (combustion state detection means) 14 for detecting the combustion state in the burner (combustor) 3. Thus, only the raw material gas is supplied to the hydrogen generator 1 and the raw material gas discharged from the hydrogen generator 1 is supplied to the burner (combustor) 3 through the fuel bypass means (bypass passage 9) for combustion. 2 (S101 and S102 in FIG. 2), supply of the source gas in the source gas combustion step, and combustion of the gas discharged from the hydrogen generator 1 in the burner (combustor) 3 while continuing the reforming water pump (reformation) Water supply ) 6 to start the water supply operation to the hydrogen generator 1 (S104 in FIG. 2) and a predetermined time (30 from the start of the water supply operation by the reforming water pump (reforming water supply means) 6). (Second) until the time elapses, whether the detection value detected by the carbon monoxide concentration detector (combustion state detection means) 14 satisfies a predetermined condition or not, and determines whether or not the water supply is abnormal. This is a method of operating a fuel cell system having steps (S105 and S106 in FIG. 2).

According to this operation method, the process shifts from the raw material gas combustion process to the water supply start process, so that a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, and the combustion state is also transient. However, in the judgment process of the next process, the transiently unstable combustion state is detected by the carbon monoxide concentration detector (combustion state detection means) 14, and the unstable combustion state It can be determined that “the water supply is not abnormal” on the basis of the detection value representing the above.

  In addition, when the water supply operation of the reforming water pump (reformed water supply means) 6 is started in the water supply start process and water supply to the hydrogen generator 1 cannot be performed due to some abnormality, the water supply operation is started. After that, since a large amount of source gas is not supplied to the burner (combustor) 3, the combustion state is also stable. However, in the determination step of the next step, this stable combustion state is detected by a carbon monoxide concentration detector ( The determination means can determine that “the water supply is abnormal” based on the detected value that is detected by the combustion state detection means) 14 and represents a stable combustion state.

  Therefore, an abnormality in water supply for hydrogen generation can be determined using a relatively inexpensive carbon monoxide concentration detector (combustion state detection means) 14 instead of an expensive sensor such as a water flow rate sensor. Thus, the cost reduction of the fuel cell system can be realized.

  The carbon monoxide concentration detector (combustion state detection means) 14 used in the present embodiment is a gas concentration detector that detects the gas concentration of a predetermined gas in the combustion exhaust gas discharged from the burner (combustor) 3. However, when the supply of water to the hydrogen generator 1 is started, a large amount of source gas is transiently supplied to the burner (combustor) 3 by the evaporated water, so that the combustion state is transiently inadequate. It becomes stable and the concentration of a specific gas such as carbon monoxide in the combustion exhaust gas changes. Therefore, by detecting the concentration of a specific gas such as carbon monoxide whose concentration changes when the combustion state in the combustion exhaust gas becomes unstable, it is determined whether or not a predetermined condition is satisfied, thereby supplying water for generating hydrogen. Can be judged. In addition, instead of the carbon monoxide concentration detector 14, an oxygen concentration detector that detects the oxygen concentration in the combustion exhaust gas discharged from the burner (combustor) 3 is used, or discharged from the burner (combustor) 3. Even when a combustible gas concentration detector that detects the concentration of combustible hydrocarbon gas contained in the raw material gas in the exhaust gas is used, the gas concentration is detected to determine whether or not a predetermined condition is met. By doing so, it is possible to determine an abnormality in water supply for hydrogen generation.

  In addition, the carbon monoxide concentration detector (combustion state detection means) 14 used in the present embodiment detects the concentration of carbon monoxide. In this embodiment, the determination means 17 includes the reforming water. When the maximum value of the carbon monoxide concentration from when the pump (reformed water supply means) 6 is operated to when a predetermined time (30 seconds) elapses is smaller than the predetermined concentration value (200 ppm) (reformed water pump (improved If the carbon monoxide concentration does not exceed the predetermined concentration value (200 ppm) after the specified water supply means) 6 is operated and the predetermined time (30 seconds) elapses, the reforming water pump (revised) The water supply from the quality water supply means 6 to the hydrogen generator 1 is judged to be abnormal. When the supply of water to the hydrogen generator 1 is started, a large amount of water is transiently caused by the evaporated water. The source gas was supplied to the burner (combustor) 3 , The combustion state becomes transiently unstable, the concentration of carbon monoxide in the combustion exhaust gas is increased.

  Therefore, the maximum detected value of the concentration of carbon monoxide in the combustion exhaust gas from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses is a predetermined concentration value. (200 ppm) or more (the detected value of the concentration of carbon monoxide in the flue gas from when the reforming water pump (reforming water supply means) 6 is operated to when a predetermined time (30 seconds) elapses) If the concentration exceeds a predetermined concentration value (200 ppm), a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, and the combustion state becomes transiently unstable. Since it can be estimated that the carbon oxide concentration has increased, it can be determined that the water supply is normal, and conversely, after the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses. Of the detected value of the concentration of carbon monoxide in the combustion exhaust gas of If the value is less than the predetermined concentration value (200 ppm) (the carbon monoxide in the combustion exhaust gas from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses). If the detected value of concentration does not become equal to or higher than the predetermined concentration value (200 ppm)), it can be determined that the water supply is abnormal because the combustion is in a stable state.

  Therefore, the carbon monoxide concentration detector (combustion state detecting means) 14 from when the reforming water pump (reforming water supply means) 6 is operated to the judgment means 17 until a predetermined time (30 seconds) elapses. When the detected maximum value of the carbon monoxide concentration in the combustion exhaust gas is smaller than a predetermined concentration value (200 ppm) (until a predetermined time (30 seconds) has elapsed since the reforming water pump (reforming water supply means) 6 was operated) When the carbon monoxide concentration in the combustion exhaust gas detected by the carbon monoxide concentration detector (combustion state detection means) 14 does not exceed a predetermined concentration value (200 ppm) during the period, a reforming water pump (reforming water supply) Means) It is determined that water supply from the hydrogen generator 1 to the hydrogen generator 1 is abnormal, and a period of time from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses. Carbon oxide concentration detector (fuel When the maximum value of the carbon monoxide concentration in the combustion exhaust gas detected by the state detection means 14 is equal to or higher than a predetermined concentration value (200 ppm) (predetermined time after operating the reforming water pump (reforming water supply means) 6) (When the carbon monoxide concentration in the combustion exhaust gas detected by the carbon monoxide concentration detector (combustion state detection means) 14 is equal to or higher than a predetermined concentration value (200 ppm)) until (30 seconds) elapses. It can be determined that the water supply from the quality water pump (reformed water supply means) 6 to the hydrogen generator 1 is normal.

  Further, in the present embodiment, when the determination unit 17 determines that the water supply from the reforming water pump (reformed water supply unit) 6 to the hydrogen generator 1 is abnormal, the hydrogen generator 1 is stopped. When the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal, the abnormality is detected and the hydrogen generator 1 (and the hydrogen generator 1) The operation of the peripheral devices such as the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation is stopped, and for example, the raw material gas supply flow path 4 is closed by an electromagnetic valve (not shown). Supply of the raw material gas to the hydrogen generator 1), the user of the fuel cell system notices that the fuel cell system has stopped abnormally, contacts the service company, and is inspected and diagnosed by a service person. , Taking part, parts replacement, malfunction repair, etc. Although the fuel cell 2 cannot generate electricity, the raw material is burned wastefully, or the hydrogen generator 1 and its peripheral devices (reformed water pump (reformed water supply means) 6 and combustion fan 13) are operated. It is possible to prevent waste of electric power and abnormal deterioration of materials such as a catalyst.

  In addition, the fuel cell system of the present embodiment includes a display 18 that displays the operating state of the fuel cell system, and the determination means 17 is connected from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1. When it is determined that the water supply is abnormal, the display 18 displays that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal. Further, in the operation method of the fuel cell system according to the present embodiment, when it is determined that the water supply is abnormal in the determination step (S105 and S106 in FIG. 2), the display 18 indicates that the water supply is abnormal. Since the display step (S107 in FIG. 2) to be performed is further provided, the display 18 indicates that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal. Fuel cell system It is possible to know the user or a service person of the arm, inspection by a service person, fault diagnosis, replacement of parts, can be performed quickly without waste the correspondence of such repair.

  In the fuel cell system according to the present embodiment, instead of the carbon monoxide concentration detector 14, an oxygen concentration detector that detects the oxygen concentration in the combustion exhaust gas discharged from the burner (combustor) 3 is used. The minimum value of the oxygen concentration after the determination unit 17 operates the reforming water pump (reforming water supply unit) 6 until a predetermined time (30 seconds) elapses is greater than the predetermined concentration value (2%). When it is large (when the oxygen concentration does not fall below the predetermined concentration value (2%) between the operation of the reforming water pump (reforming water supply means) 6 and the elapse of a predetermined time (30 seconds)) Determines that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal, and evaporates when the water supply to the hydrogen generator 1 is started. A large amount of material gas is transiently burned by burned water (combustor To be supplied to 3, the oxygen required for combustion of the raw material gas is insufficient, transient oxygen concentration decreases.

  Accordingly, the minimum value of the detected value of the oxygen concentration in the combustion exhaust gas from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses is the predetermined concentration value (2% ) (The detected value of the oxygen concentration in the combustion exhaust gas is a predetermined concentration value (2) after the predetermined time (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated. %) Or less), a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, so that oxygen necessary for combustion of the raw material gas is insufficient, and carbon monoxide in the combustion exhaust gas. Since it can be estimated that the concentration has decreased, it can be determined that the water supply is normal, and conversely, the combustion from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses. If the minimum value of the detected oxygen concentration in the exhaust gas exceeds the specified concentration value (2%) (If the predetermined value (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated, the detected value of the oxygen concentration in the combustion exhaust gas is less than the predetermined concentration value (2%). Otherwise, it can be determined that the water supply is abnormal because the combustion remains stable.

  Therefore, the oxygen concentration in the combustion exhaust gas detected by the oxygen concentration detector during the predetermined time (30 seconds) after the reforming water pump (reformed water supply unit) 6 is operated by the judgment unit 17 is determined. When the minimum value exceeds the predetermined concentration value (2%) (the carbon monoxide concentration is detected after the predetermined time (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated) (When the oxygen concentration in the combustion exhaust gas detected by the combustor (combustion state detection means) 14 does not fall below the predetermined concentration value (2%)) from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 In the combustion exhaust gas detected by the oxygen concentration detector during a predetermined time (30 seconds) after the reforming water pump (reforming water supply means) 6 is operated. The minimum oxygen concentration is less than the predetermined concentration value (2%) The oxygen concentration in the combustion exhaust gas detected by the oxygen concentration detector after the predetermined time (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated. (When 2% or less), it can be determined that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is normal.

  Further, in the fuel cell system of the present embodiment, in place of the carbon monoxide concentration detector 14, the combustible hydrocarbon gas contained in the raw material gas in the combustion exhaust gas discharged from the burner (combustor) 3 is used. In the case of using a combustible gas concentration detector that detects the concentration, the combustible gas is combustible during a predetermined time (30 seconds) after the determination unit 17 operates the reforming water pump (reforming water supply unit) 6. When the maximum value of the gas concentration is smaller than the predetermined concentration value (3000 ppm) (the combustible gas concentration is between the time when the reforming water pump (reforming water supply means) 6 is operated and the predetermined time (30 seconds) elapses). The case where the concentration does not exceed the predetermined concentration value (3000 ppm)) is to judge that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal, and the hydrogen generator Supply of water to 1 When started, a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, so that the combustion becomes transiently unstable and part of the raw material gas is discharged unburned. The

Therefore, the maximum value of the detected value of the combustible gas concentration in the combustion exhaust gas from when the reforming water pump (reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses is the predetermined concentration value (3000 ppm). ) If it is above (the detected value of the combustible gas concentration in the combustion exhaust gas from the time when the reformed water pump (reformed water supply means) 6 is operated until a predetermined time (30 seconds) elapses) 3000 ppm) or more), a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, the combustion becomes transiently unstable, and a part of the raw material gas remains unburned. Since it can be estimated that the concentration of combustible gas in the exhaust gas is increased, the water supply can be determined to be normal. Conversely, a predetermined time (30) after the reforming water pump (reforming water supply means) 6 is operated. Combustible in the flue gas until the second) If the maximum detected value of the gas concentration is less than the predetermined concentration value (3000 ppm) (combustion after the predetermined time (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated) If the combustible gas concentration in the exhaust gas is not equal to or higher than the predetermined concentration value (3000 ppm), the combustion is in a stable state, so it can be determined that the water supply is abnormal.

  Therefore, the combustible gas in the combustion exhaust gas detected by the combustible gas concentration detector after the predetermined time (30 seconds) elapses after the determination means 17 operates the reforming water pump (reforming water supply means) 6. When the maximum value of the concentration is smaller than the predetermined concentration value (3000 ppm) (the combustible gas concentration detector is not activated until the predetermined time (30 seconds) elapses after the reforming water pump (reforming water supply means) 6 is operated). If the detected combustible gas concentration in the flue gas does not exceed the predetermined concentration value (3000 ppm)), it is determined that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal. And the maximum value of the combustible gas concentration in the combustion exhaust gas detected by the combustible gas concentration detector during the predetermined time (30 seconds) after the reforming water pump (reforming water supply means) 6 is operated. Predetermined concentration value ( (000 ppm) or more (combustible gas in the combustion exhaust gas detected by the combustible gas concentration detector during the predetermined time (30 seconds) after the reforming water pump (reforming water supply means) 6 is operated) When the gas concentration is equal to or higher than the predetermined concentration value (3000 ppm), it can be determined that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is normal.

(Embodiment 2)
FIG. 3 is a block diagram showing the configuration of the fuel cell system according to Embodiment 2 of the present invention.

  As shown in FIG. 3, the fuel cell system according to the present embodiment is a carbon monoxide concentration detector (combustion state detection means) 14 as a combustion state detection means in the fuel cell system according to the first embodiment shown in FIG. The flame rod 19 is detected as a flame detector that detects the flame of the burner (combustor) 3 and outputs a flame current whose output current value changes according to the detected flame. Is the same as the fuel cell system of the first embodiment shown in FIG.

  The flame rod 19 monitors the flame state when combustion is continued in the burner (combustor) 3, and the predetermined means 17 operates after the reforming water pump (reformed water supply means) 6 operates. When the output current value of the frame rod 19 decreases to a value at which it can be determined that the flame of the burner (combustor) 3 has disappeared after a lapse of time (30 seconds), the control unit 16 causes the flame of the burner (combustor) 3 to disappear. It is determined that the system operation is abnormal, and a display indicating an abnormality due to the disappearance of the flame in the burner is displayed on the display 18. The display indicating the abnormality due to the disappearance of the flame in the burner may be a character string such as “misfire abnormality”, or a so-called error code combining alphabets and numbers.

  The frame rod 19 as a constituent member in the present embodiment is an example of a specific implementation of a flame detector as a combustion state detection means.

The fuel cell system in the present embodiment is supplied from a reforming water supply channel 5 and a hydrocarbon-based source gas such as city gas or propane gas supplied from the source gas supply channel 4 using a catalyst. A hydrogen generating device 1 for generating a fuel gas mainly composed of hydrogen from the water, a fuel gas generated by the hydrogen generating device 1 and supplied from the fuel gas supply flow path 7, and an air supply means (not shown) The fuel cell 2 that generates power using oxygen contained in the air supplied from the above) and the combustion air is supplied by the combustion fan 13 and the hydrogen generator 1 starts supplying the source gas to the hydrogen generator 1. Until the generated fuel gas is supplied to the fuel cell 2, the gas discharged from the hydrogen generator 1 is burned using the combustion air supplied by the combustion fan 13, and the fuel gas is supplied to the fuel cell 2. Beginning A burner (combustor) 3 that heats the catalyst in the hydrogen generator 1 by combusting fuel gas that has not been consumed in the fuel cell 2 by using combustion air supplied by the combustion fan 13, and reforming A reformed water pump (reformed water supply means) 6 that is provided in the water supply channel 5 and supplies water to the hydrogen generator 1 and a fuel gas that can be supplied to the fuel cell 2 in the hydrogen generator 1 can be generated. In order to supply the gas discharged from the hydrogen generator 1 to the burner (combustor) 3 without supplying it to the fuel cell 2 until it becomes (fuel gas supply flow path 7 and fuel cell 2 A fuel gas discharge passage 8 that discharges fuel gas that has not been used for power generation and supplies the burner (combustor) 3 to the fuel gas discharge passage 8 branches from the middle of the fuel gas supply passage 7. Bypass passage 9 and fuel gas supply The fuel cell from the junction of the solenoid valve 10 provided in the fuel gas supply channel 7 on the fuel cell 2 side from the branch point to the bypass channel 9 in the path 7 and the bypass channel 9 in the fuel gas discharge channel 8 Combustion exhaust gas flow for discharging the combustion exhaust gas of the burner (combustor) 3 from the electromagnetic valve 11 provided in the fuel gas discharge flow path 8 on the second side, the electromagnetic valve 12 provided in the bypass flow path 8) A flame rod 19 as a flame detector (combustion state detection means) that detects a flame of the passage 15 and a burner (combustor) 3 and outputs a flame current whose output current value changes according to the detected flame; 16 and a display 18 for displaying the operating state of the fuel cell system.

  The control unit 16 supplies only the source gas to the hydrogen generator 1 and supplies the source gas discharged from the hydrogen generator 1 to the burner (combustor) 3 through the fuel bypass means. If a predetermined condition such that the temperature of the catalyst reaches a predetermined temperature after starting combustion is satisfied, the reforming water pump (reforming water supply means) 6 is operated, and the reforming water pump (reforming water supply means) 6 is operated. Detected value detected by the flame rod 19 as a flame detector (combustion state detection means) after a predetermined time elapses from the operation of the flame (flame current output according to the detected flame of the burner (combustor) 3) Whether or not the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal is determined based on whether or not the value) satisfies a predetermined condition (1 μA or less) (flame detection) As a detector (combustion state detection means) A determination means for determining that the flame rod 19 detects the flame of the burner (combustor) 3 and outputs a flame current value of 1 μA or less, normal if it exceeds 1 μA, and abnormal) 17. When the control unit 16 determines that the water supply from the reforming water pump (reforming water supply unit) 6 to the hydrogen generator 1 is abnormal by the determination unit 17, the control unit 16 supplies the water to the display unit 18. Is displayed, and the operation of the peripheral devices such as the hydrogen generator 1 and the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation of the hydrogen generator 1 is stopped. At the same time, for example, the source gas supply flow path 4 is closed by a solenoid valve (not shown), and the supply of the source gas to the hydrogen generator 1 is stopped.

  The operation of the fuel cell system of the present embodiment configured as described above will be described below using the flowchart shown in FIG.

  When an operation for supplying fuel gas from the hydrogen generator 1 to the fuel cell 2 (operation for generating electricity with the fuel cell 2) is started, first, a raw material gas combustion process (supplying only the raw material gas to the hydrogen generator 1) Then, the step of supplying the raw material gas discharged from the hydrogen generator 1 to the burner (combustor) 3 through the fuel bypass means and burning it is started.

  In the source gas combustion process, first, only source gas is supplied to the hydrogen generator 1 through the source gas supply channel 4 (S201). At this time, since the solenoid valves 10 and 11 are in the closed state and the solenoid valve 12 is in the open state, the raw material gas supplied to the hydrogen generator 1 is supplied from the hydrogen generator 1 to the fuel gas supply flow path 7 and the bypass. The gas is supplied to the burner (combustor) 3 through the flow path 9 and the fuel gas discharge flow path 8.

Combustion air is also supplied to the burner (combustor) 3 by the combustion fan 13, and ignition and combustion are started by operating an igniter (not shown) (S202). Whether the catalyst of the hydrogen generator 1 is heated by the combustion of the burner (combustor) 3 and whether or not the temperature has risen to a temperature at which water can be supplied to the hydrogen generator 1, is necessary in the periphery of the catalyst of the hydrogen generator 1. (S203), and waits for the temperature to rise to a temperature at which water can be supplied to the hydrogen generator 1.

  And when it will be in the temperature state which can supply water to the hydrogen production | generation apparatus 1, a raw material gas combustion process will be complete | finished and it will be discharged | emitted from a water supply start process (supply of the raw material gas in a raw material gas combustion process and a hydrogen production | generation apparatus) The process proceeds to the step of starting the water supply operation to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 while continuing the combustion of the gas in the burner (combustor) 3.

  In the water supply start process, water supply operation to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 is started (S204). When the water supply start process is completed, the determination process (frame as a flame detector (combustion state detection means) from the start of the water supply operation by the reforming water pump (reformed water supply means) 6 until a predetermined time elapses). The process proceeds to a step of determining whether or not the water supply is abnormal depending on whether the flame current value output by the rod 19 satisfies the predetermined condition or not.

  In the determination step, the determination means 17 determines whether or not the flame current value of the frame rod 19 as a flame detector (combustion state detection means) is a predetermined value of 1 μA or less (S205).

  A flame detector (combustion) between the time when a predetermined time (in this embodiment, 30 seconds) elapses after the control unit 16 causes the reforming water pump (reforming water supply means) 6 to perform the water supply operation. If the flame current value of the frame rod 19 as the state detection means is equal to or less than a predetermined value of 1 μA, the water supply to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 is normal. The determination means 17 determines that S205 is branched to Yes and proceeds to the next step S208, where carbon monoxide in the fuel gas generated by the hydrogen generator 1 does not deteriorate the catalytic performance of the fuel cell 2. When the concentration is sufficiently reduced, the shutoff valves 10 and 11 are opened and the shutoff valve 12 is closed, thereby closing the bypass passage 9 and supplying the fuel gas to the fuel cell 2 through the fuel gas supply passage 7. The battery 2 is a hydrogen generator 1 Made is a fuel gas supplied from the fuel gas supply passage 7, to generate electric power by electrochemical reaction and oxygen contained in the supplied air from the air supply means (not shown).

  If the control unit 16 causes the reforming water pump (reforming water supply means) 6 to perform the water supply operation, a predetermined period of time (in this embodiment, 30 seconds) elapses before the flame detector. If the flame current value of the flame rod 19 as the (combustion state detection means) does not become a predetermined value of 1 μA or less, the reforming water pump (reforming water supply means) 6 supplies water to the hydrogen generator 1. The determination means 17 determines that there is an abnormality, branches S206 to the Yes side, proceeds to the next step S207, and causes the display 18 to display that the water supply is abnormal (S207). The operation of the peripheral devices such as the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation of the apparatus 1 and the hydrogen generator 1 is stopped, and, for example, the raw material gas supply flow path 4 is connected to the solenoid valve Closed (not shown) to generate hydrogen To stop the supply of the raw material gas to the location 1 (S209). These series of operations are controlled and operated by the control unit 16.

  In the present embodiment, the predetermined time from the start of water supply when determining whether or not there is an abnormality in the water supply to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 is used. , 30 seconds, but it is not necessarily strictly 30 seconds. The temperature rise time from the catalyst temperature at the start of the reforming water supply to the temperature at which no catalyst deterioration of the hydrogen generator 1 occurs in the absence of water supply. It can be set appropriately within a shorter time range.

Further, in the present embodiment, the predetermined value of the flame current value of the frame rod 19 as the flame detector (combustion state detection means) is 1 μA, but it is not necessarily strictly 1 μA, and the burner (combustor) 3 It can be set appropriately within a range smaller than the output value of the frame rod 19 at the time of stable combustion. Further, it may be set in advance as described above, or may be set by the control unit 16 with reference to the flame current value of the frame rod 19 detected in step S203 of the above-described starting operation. In general gas water heaters, it is known that the output when city gas is stably burned is about 10 μA.

  In step S204, when the reforming water supply is started, a large amount of raw material gas is transiently transferred to the burner (combustor) 3 through the fuel gas supply channel 7, the bypass channel 9, and the fuel gas discharge channel 8 by the evaporated water. Since the fuel is supplied, the flame floats from the burner (combustor) 3, and the output signal as the flame current value of the frame rod 19 decreases.

  Taking the configuration and operating method of the fuel cell system in the present embodiment, when the output signal, which is a detected value indicating the unstable combustion state, falls below a predetermined value (for example, 1 μA), the judging means 17 It can be determined that the water supply is not abnormal. On the other hand, in step S204, when water supply cannot be performed due to some abnormality when the reforming water supply is started, a large amount of source gas is supplied from the fuel gas supply channel 7, the bypass channel 9, and the fuel gas after the water supply is started. Since it is not supplied to the burner (combustor) 3 through the discharge channel 8, the combustion state is stable, and the output signal as the flame current value of the frame rod 19 does not decrease. When the output signal as the flame current value of the frame rod 19 in the stable combustion state is a predetermined value (for example, 1 μA) or more, the determination means 17 can determine that “the water supply is abnormal”. Therefore, it is possible to determine an abnormality in the water supply for hydrogen generation without using an expensive sensor such as a water flow sensor as in the conventional fuel cell system, so that the cost of the fuel cell system can be reduced. it can.

  Further, taking the configuration and operation method of the fuel cell system in the present embodiment, the determination means 17 determines that the water supply is abnormal, and displays on the display 18 that the water supply is abnormal. can do. Therefore, when “water supply is abnormal”, it is possible to notify the user or maintenance person that “water supply is abnormal”.

As described above, the fuel cell system according to the present embodiment includes the hydrogen generator 1 that generates a fuel gas containing hydrogen as a main component from the raw material gas and water using the catalyst, and the fuel generated by the hydrogen generator 1. The fuel cell 2 that generates power using gas and air, and the hydrogen generator 1 from when the raw material gas starts to be supplied to the hydrogen generator 1 until the fuel gas generated by the hydrogen generator 1 is supplied to the fuel cell 2 A burner (combustor) 3 that burns fuel gas that has not been consumed in the fuel cell 2 and heats the catalyst in the hydrogen generator 1 by burning the gas discharged from the fuel cell 2 and starting to be supplied to the fuel cell 2. Hydrogen generation until the hydrogen generator 1 can generate fuel gas that can be supplied to the fuel cell 2 by the reforming water pump (reforming water supply means) 6 that supplies water to the hydrogen generator 1 Waste from device 1 Bypass means (fuel gas supply flow path 7, fuel gas discharge flow path 8, bypass flow path 9 and electromagnetic) for supplying the burned gas to the burner (combustor) 3 without supplying it to the fuel cell 2 Flame detector (combustion state detection means) that detects a flame of the valve 10, 11, 12) and the burner (combustor) 3 (detects the combustion state) and outputs a flame current whose output current value changes according to the detected flame ) As a frame rod 19 and a control unit 16. The control unit 16 supplies only the source gas to the hydrogen generator 1 and discharges the source gas discharged from the hydrogen generator 1 through the fuel bypass means (burner). If the predetermined condition is satisfied after the combustion is started by the burner (combustor) 3, the reforming water pump (reforming water supply means) 6 is operated and the reforming water pump (reforming) Water supply means) 6 after operating A detection value (a flame current value output according to the detected flame of the burner (combustor) 3) detected by the flame rod 19 as a flame detector (combustion state detection means) until the time elapses is a predetermined condition ( It is determined whether or not the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal (flame detector (combustion state detection means)). ) Is detected as normal when the flame current value detected and output by the flame rod 19 of the burner (combustor) 3 is 1 μA or less, and abnormal when the state exceeding 1 μA is maintained) This is a fuel cell system having a judging means 17 for performing the above.

  According to the above configuration, only the raw material gas is supplied to the hydrogen generator 1, the raw material gas discharged from the hydrogen generator 1 is supplied to the burner (combustor) 3 through the fuel bypass means (bypass passage 9), After the combustion is started by the burner (combustor) 3, the reforming water pump (reforming water supply means) 6 is operated so that the reforming water pump (reforming water supply means) 6 is supplied to the hydrogen generator 1. When the supply of water is started, a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, and the flame is transiently floated from the burner (combustor) 3 so that the flame is burned. The output signal as the flame current value of the frame rod 19 is lowered when the flame rod 19 floats from the (combustor) 3, but the combustion state in which the flame floats from the burner (combustor) 3 is transient. As a flame detector (combustion state detection means) Detected by the frame rods 19, can be detected value representing the state of combustion becomes unstable (flame current value) is judging means 17 based on determining the "water supply is not abnormal."

  Further, only the raw material gas is supplied to the hydrogen generator 1, and the raw material gas discharged from the hydrogen generator 1 is supplied to the burner (combustor) 3 through the fuel bypass means (bypass passage 9), and the burner (combustion) is supplied. The reforming water pump (reforming water supply means) 6 was operated after the combustion was started in the reactor 3, but the hydrogen generator 1 from the reforming water pump (reforming water supply means) 6 due to some abnormality. When water cannot be supplied to the tank, a stable combustion state is maintained even after the reforming water pump (reforming water supply means) 6 is operated. This stable combustion state is detected by a flame detector (combustion state). Based on the detection value (flame current value) that is detected by the frame rod 19 as the detection means) and indicates a stable combustion state, the determination means 17 can determine that “the water supply is abnormal”.

  Therefore, instead of an expensive sensor such as a water flow rate sensor, the flame rod 19 as a relatively inexpensive flame detector (combustion state detection means) can be used to determine an abnormality in water supply for hydrogen generation. Therefore, the cost reduction of the fuel cell system can be realized.

As described above, the operation method of the fuel cell system according to the present embodiment includes the hydrogen generator 1 that generates a fuel gas mainly composed of hydrogen from the raw material gas and water using the catalyst, and the hydrogen generator 1 generates the fuel gas. The fuel cell 2 that generates power using the generated fuel gas and air, and the hydrogen gas from the start of supply of the raw material gas to the hydrogen generator 1 until the fuel gas generated by the hydrogen generator 1 is supplied to the fuel cell 2 A burner (combustion) that heats the catalyst in the hydrogen generator 1 by burning the fuel gas that has not been consumed in the fuel cell 2 after the gas discharged from the generator 1 is combusted and the fuel gas begins to be supplied to the fuel cell 2 3), a reforming water pump (reforming water supply means) 6 for supplying water to the hydrogen generator 1, and a fuel gas that can be supplied to the fuel cell 2 in the hydrogen generator 1. Until hydrogen generation equipment Fuel bypass means (fuel gas supply flow path 7, fuel gas discharge flow path 8, and bypass flow path 9 for supplying gas discharged from 1 to the burner (combustor) 3 without supplying it to the fuel cell 2 And a flame detector (combustion) for detecting a flame of the burner (combustor) 3 (detecting the combustion state) and outputting a flame current whose output current value changes according to the detected flame. This is a method of operating a fuel cell system including a frame rod 19 as a state detection means), which supplies only the raw material gas to the hydrogen generator 1 and supplies the raw material gas discharged from the hydrogen generator 1 to the fuel bypass means ( A raw material gas combustion process (S201 and S202 in FIG. 4) that is supplied to the burner (combustor) 3 through the bypass flow path 9) and combusted, and the supply of the raw material gas and the exhaust gas from the hydrogen generator 1 in the raw material gas combustion process. Water supply start step (S204 in FIG. 4) for starting the water supply operation to the hydrogen generator 1 by the reforming water pump (reforming water supply means) 6 while continuing combustion in the burner (combustor) 3 of the generated gas ) And a flame rod 19 as a flame detector (combustion state detection means) from the start of the water supply operation by the reforming water pump (reformed water supply means) 6 until a predetermined time (30 seconds) elapses. The reformed water pump (reformed water supply means) 6 determines whether the detected value (the flame current value output in accordance with the detected flame of the burner (combustor) 3) satisfies the predetermined condition (1 μA or less) or not. Whether or not the water supply to the hydrogen generator 1 is abnormal is determined by the flame rod 19 as a flame detector (combustion state detection means) detecting the flame of the burner (combustor) 3 and outputting the flame current The value should be 1μA or less Normal if a method of operating a fuel cell system having a process determining the abnormal judgment) if the remains of more than 1 .mu.A (S205 and S206 in FIG. 4).

  According to this operation method, the process shifts from the raw material gas combustion process to the water supply start process, so that a large amount of raw material gas is transiently supplied to the burner (combustor) 3 by the evaporated water, and the combustion state is also transient. However, in the determination process of the next step, the transiently unstable combustion state is detected by the flame rod 19 as a flame detector (combustion state detection means), and the unstable combustion Based on the detected value representing the state (determination means 17), it can be determined that “the water supply is not abnormal”.

  In addition, when the water supply operation of the reforming water pump (reformed water supply means) 6 is started in the water supply start process and water supply to the hydrogen generator 1 cannot be performed due to some abnormality, the water supply operation is started. After that, since a large amount of source gas is not supplied to the burner (combustor) 3, the combustion state is also stable, but this stable combustion state is detected by a flame detector (combustion state detection) in the next determination step. The determination means can determine that “the water supply is abnormal” based on the detected value representing the stable combustion state detected by the frame rod 19 as the means).

  Therefore, instead of an expensive sensor such as a water flow rate sensor, the flame rod 19 as a relatively inexpensive flame detector (combustion state detection means) can be used to determine an abnormality in water supply for hydrogen generation. Therefore, the cost reduction of the fuel cell system can be realized.

  In addition, the fuel cell system of the present embodiment detects the flame of the burner (combustor) 3 (detects the combustion state) as the combustion state detection means, and outputs a flame current whose output current value changes according to the detected flame. The frame rod (flame detector) 19 is used and the determination means 17 starts the water supply operation of the reforming water pump (reforming water supply means) 6 until a predetermined time (30 seconds) elapses. The minimum value of the detection value (flame current value output according to the detected flame of the burner (combustor) 3) detected by the frame rod 19 as a flame detector (combustion state detection means) is larger than a predetermined value (1 μA). In this case, it is determined that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal.

  When the supply of water to the hydrogen generator 1 is started, a large amount of source gas is transiently supplied to the burner (combustor) 3 by the evaporated water, so that the flame floats from the burner (combustor) 3. As a result, the output current of the frame rod (flame detector) 19 decreases. On the contrary, since there is no supply of water to the hydrogen generator 1, when there is no transient large amount of source gas supply, the flame is stably formed in the burner (combustor) 3, and the flame rod (flame detector) ) The output current of 19 is also stabilized. Therefore, the minimum value of the output current of the frame rod (flame detector) 19 after the reforming water pump (reforming water supply means) 6 is operated and until a predetermined time (30 seconds) elapses is a predetermined value (1 μA). ) (The output current of the flame rod (flame detector) 19 is a predetermined value (1 μA) between the operation of the reforming water pump (reforming water supply means) 6 and the elapse of a predetermined time (30 seconds). ) If not, the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 can be determined to be abnormal. When the minimum value of the output current of the frame rod (flame detector) 19 is less than or equal to a predetermined value (1 μA) from when the reforming water supply means) 6 is operated until a predetermined time (30 seconds) elapses (improved) Activate the quality water pump (reformed water supply means) 6 When the output current of the flame rod (flame detector) 19 becomes a predetermined value (1 μA) or less after a predetermined time (30 seconds) elapses, the reforming water pump (reforming water supply means) ) It can be determined that the water supply from 6 to the hydrogen generator 1 is normal.

  Further, when a flame rod (flame detector) 19 for detecting a flame in the burner (combustor) 3 is used as a combustion state detecting means for detecting the stability / instability of the combustion state, a transient state accompanying the start of water supply is used. When there is a large amount of source gas supply, the flame floats from the burner (combustor) 3 and the output current of the flame rod (flame detector) 19 decreases. When there is no transient large amount of source gas supply, the flame Since the flame rod (flame detector) 19 is stably formed in the burner (combustor) 3 and the output current of the flame rod (flame detector) 19 is also stable, the flame rod (flame detector) is a detection value that changes according to the stability and instability of the combustion state. ) It is useful because the judgment means 17 can judge whether or not the water supply is abnormal from the output signal 19).

  Further, in the present embodiment, when the determination unit 17 determines that the water supply from the reforming water pump (reformed water supply unit) 6 to the hydrogen generator 1 is abnormal, the hydrogen generator 1 is stopped. When the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal, the abnormality is detected and the hydrogen generator 1 (and the hydrogen generator 1) The operation of the peripheral devices such as the reforming water pump (reforming water supply means) 6 and the combustion fan 13 related to the operation is stopped, and for example, the raw material gas supply flow path 4 is closed by an electromagnetic valve (not shown). Supply of the raw material gas to the hydrogen generator 1), the user of the fuel cell system notices that the fuel cell system has stopped abnormally, contacts the service company, and is inspected and diagnosed by a service person. , Taking part, parts replacement, malfunction repair, etc. Although the fuel cell 2 cannot generate electricity, the raw material is burned wastefully, or the hydrogen generator 1 and its peripheral devices (reformed water pump (reformed water supply means) 6 and combustion fan 13) are operated. It is possible to prevent waste of electric power and abnormal deterioration of materials such as a catalyst.

  In addition, the fuel cell system of the present embodiment includes a display 18 that displays the operating state of the fuel cell system, and the determination means 17 is connected from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1. When it is determined that the water supply is abnormal, the display 18 displays that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal. Further, in the operation method of the fuel cell system of the present embodiment, when an abnormality in water supply is determined in the determination step (S205 and S206 in FIG. 4), the display 18 indicates that the water supply is abnormal. Since the display step (S207 in FIG. 4) to be performed is further provided, the display 18 indicates that the water supply from the reforming water pump (reforming water supply means) 6 to the hydrogen generator 1 is abnormal. Fuel cell system It is possible to know the user or a service person of the arm, inspection by a service person, fault diagnosis, replacement of parts, can be performed quickly without waste the correspondence of such repair.

  The fuel cell system and the operation method of the fuel cell system according to the present invention include, for example, a relatively inexpensive combustion state detection unit such as a carbon monoxide concentration detector or a flame detector instead of an expensive sensor such as a water flow rate sensor. Therefore, it is possible to determine an abnormality in the supply of water for hydrogen generation, which is optimal for a home fuel cell system equipped with a hydrogen generation apparatus that requires cost reduction.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Fuel cell 3 Burner 6 Reformed water pump 7 Fuel gas supply flow path 8 Fuel gas discharge flow path 9 Fuel gas bypass flow path 10, 11, 12 Solenoid valve 14 Carbon monoxide concentration detector 16 Control part 17 Judgment means 18 Indicator 19 Frame rod

Claims (12)

A hydrogen generator that generates a fuel gas mainly composed of hydrogen from a raw material gas and water using a catalyst;
A fuel cell that generates power using the fuel gas and air generated by the hydrogen generator;
The fuel gas generated from the hydrogen generator is combusted until the fuel gas generated in the hydrogen generator is supplied to the fuel cell after the source gas is supplied to the hydrogen generator. A combustor that heats the catalyst by burning the fuel gas that has not been consumed in the fuel cell after it has been supplied to the fuel cell;
Reforming water supply means for supplying water to the hydrogen generator;
Supplying the gas discharged from the hydrogen generation device to the combustor without supplying the fuel cell until the fuel gas in a state that can be supplied to the fuel cell can be generated in the hydrogen generation device. Fuel bypass means;
Combustion state detection means for detecting a combustion state in the combustor;
After supplying only the raw material gas to the hydrogen generator and supplying the raw material gas discharged from the hydrogen generator to the combustor through the fuel bypass means and starting combustion in the combustor and the reforming water supply means Ru to operate the control unit satisfies the condition,
The Oite during a period from the reforming water supply means is operated until a predetermined time elapses, the water from the combustor stable the Invite combustion state is long as it is maintained reforming water supply means to the hydrogen generator A determination means for determining that an abnormality has occurred due to a decrease in the supply amount ;
A fuel cell system comprising: 2. The fuel cell system according to claim 1, wherein the combustion state detection means is a gas concentration detector that detects a gas concentration of a predetermined gas in the combustion exhaust gas discharged from the combustor. The fuel cell system according to claim 2, wherein the predetermined gas is carbon monoxide. The fuel cell system according to claim 2, wherein the predetermined gas is a hydrocarbon-based gas of methane or propane contained in the raw material gas. When the maximum value of the gas concentration is less than a predetermined concentration value after the predetermined time elapses after the reforming water supply unit is operated, the determination unit sends the hydrogen generating device to the reforming water supply unit. The fuel cell system according to claim 3 or 4, wherein it is determined that an abnormality has occurred due to a decrease in the amount of water supplied to the water. The fuel cell system according to claim 2, wherein the predetermined gas is oxygen. If the minimum value of the gas concentration from when the reforming water supply unit is operated to when a predetermined time elapses is greater than a predetermined concentration value, the determination unit performs the hydrogen generation device from the reforming water supply unit. The fuel cell system according to claim 6, wherein it is determined that an abnormality has occurred due to a decrease in the amount of water supplied to the water. The combustion state detection means is a flame detector that detects a flame in the combustor and outputs a current, and the determination means is a period from when the reforming water supply means is operated until a predetermined time elapses. When the minimum value of the output current of the flame detector at is greater than a predetermined value, it is determined that an abnormality has occurred due to a decrease in the amount of water supplied from the reforming water supply means to the hydrogen generator. Item 4. The fuel cell system according to Item 1. 9. The hydrogen generation apparatus according to claim 1, wherein the hydrogen generation apparatus is stopped when the determination means determines that an abnormality has occurred due to a decrease in the amount of water supplied from the reforming water supply means to the hydrogen generation apparatus. 2. The fuel cell system according to item 1. An indicator for displaying the operating state of the fuel cell system, and when the judging means judges an abnormality in water supply from the reforming water supply means to the hydrogen generator, the reforming water is displayed on the indicator; The fuel cell system according to any one of claims 1 to 9, wherein a display indicating that an abnormality has occurred due to a decrease in the amount of water supplied from a supply means to the hydrogen generator is generated . A hydrogen generator that generates a fuel gas mainly composed of hydrogen from a raw material gas and water using a catalyst;
A fuel cell that generates power using the fuel gas and air generated by the hydrogen generator;
The fuel gas generated from the hydrogen generator is combusted until the fuel gas generated in the hydrogen generator is supplied to the fuel cell after the source gas is supplied to the hydrogen generator. A combustor that heats the catalyst by burning the fuel gas that has not been consumed in the fuel cell after it has been supplied to the fuel cell;
A reforming water supply means for supplying water to the hydrogen generator,
Supplying the gas discharged from the hydrogen generation device to the combustor without supplying the fuel cell until the fuel gas in a state that can be supplied to the fuel cell can be generated in the hydrogen generation device. Fuel bypass means;
An operation method of a fuel cell system comprising a combustion state detection means for detecting a combustion state in the combustor,
A raw material gas combustion step of supplying only the raw material gas to the hydrogen generator and supplying the raw material gas discharged from the hydrogen generator to the combustor through the fuel bypass means;
Water supply operation to the hydrogen generator is started by the reforming water supply means while continuing the supply of the source gas in the source gas combustion process and the combustion of the gas discharged from the hydrogen generator in the combustor. A water supply start process;
The Oite between the start of the water supply operation by reforming water supply means until a predetermined time elapses, the combustor the hydrogen generator from the reforming water supply means when a stable combustion state is long as is maintained in the A method of operating a fuel cell system comprising a determination step of determining that an abnormality has occurred due to a decrease in the amount of water supplied to the water . An operation method of the fuel cell system, further comprising an indicator for displaying an operation state of the fuel cell system, wherein a water supply amount from the reforming water supply means to the hydrogen generator is reduced in the determination step. The method of operating a fuel cell system according to claim 11, further comprising a display step of performing a display indicating the abnormality when it is determined that an abnormality due to being present has occurred .

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